Valve-stem base or pad



W. I: BISHOP.

VALVE STEMBASE 0R PAD.

APPLICATION FILED MAYs. I91e.

1,363,323@ Patented Dec. 28,1920.

II III.

STATES Parent critics.

'WILLIAM F. BISHOP, 0F WASHINGTON, DISTRICT 0F COLUMBIA.

VALVE-STEM BASE OR PAD.

Lacasse.

Application led May 3, 1916. Serial No. 95,210.

To all whom t may concern.'

Be it known that l, WILLIAM F. BISHOP, a citizen of the United States, residing at Washington, District of Columbia,liave invented certain new and useful lmprovements in Valve-Stem Bases or Pads, of which the following is a specification.

rlhis invention relates to the pads employed as the base for the valve stems of pneumatic t-i-res, and, while designed with special reference to use with the innertubes of double tube tires, it is obviously applicable to other .structures adapted to be inflated through the well known valve stems.

ln the manufacture of the inner tubes of pneumatic tires it is customary to reinforce the pure rubber of the inner tube at thev point apertured for the/reception of the valve stem by what is known as ,a pad (usually formed, in part at least, of fabric) cemented either to the inner or outer surface of the tube, and to then insert the valve stem from the ,inside of the tube through a circular aperture cut through the associated tube and pad, and then apply the `washer l and clamp nut on the exterior of the tube.

lt has been proposed to embed within the thickness of an inner tube one or more'thickuesscs of fabric provided with a slit or elliptical orifice arranged longitudinally of the tube, to the end that the head or button of a valve stem may be inserted from the eX- terior of the tube.

The object of my invention is to provide an air containing body, such as the inner tube of a tire, with a pad which will permit of the insertion of the head of the valve stem from the exterior of the tube and insure against lateralexpansion or stretch of the tube adjacent the valve stem orifice while permitting limited expansion or stretch in thereto. It further consists in an inner tube for tires provided with a multi-ply pad permitting yield or stretch circumferentially,

but preventing yield transversely. It further consists in an inner tube for tires having incorporated-between its exposed surfaces a multi-ply pad designed to yield or stretch circumferentially of the tube, but to prevent yield or stretch transversely thereof.

In the accompanying drawing illustrating embodiments of my invention:

Figure l is a plan view of a short section of an inner tube provided with my improved tube base, certain parts being broken away to show the relation of parts concealed in a complete tube.

Fig. 2 is a similar view, the tube base being shown as apertured to permit the insertion of the head of the valve stem.

Fig. 3 is a longitudinal section taken on the line -B of Fig. 1. 4

Fig. t is a transverse section of the tube, showing the valve stem and its adjuncts in operative position.

Fig. 5 is'a plan view of a stem base having additional plies for a heavier tube, parts broken away to show relative positions of underlying parts.

i Fig. 6 is a plan view looking at the opposite side of the valve-stem base or pad constructed as in Fig. 5.

Fig. 7 is an edge view of my valve-stem base or pad shown in Figs. 5 and 6.

Fig. 8 is a plan view of the pad looking at the side opposite that shown in Fig. l.

The same reference characters are used in' the several figures to designate identical parts.

VMy valve-stem base or pad, as a whole, when used with an inner tube is preferably oval in contour and is of multiple-ply con- 1 struction, the plies being of ,greater or less number to suit the pressure or weight adapted for the diameter of the tire with which it im@ is to be used or the inner tube to which it is to be applied or to be embodied-as an integral part, and the aperture therethrough for the valve stem will be of such diameter as to snugly fit the reduced part of the valve stem 105 plies of fabric and an interposed ply of unvulcanized rubber, but after vulcanization the rubber ply will be incorporated with the. fabric, thus constituting a two-ply pad.

rThis valve-stem base or pad, referring to Figs. l to 4, prior to vulcanization is of three-ply construction and comprises a preferably oval blank of unvulcanized sheet rubber l provided on one side with two rsimilar semi-oval patches 2 and 3 of frietioned or rubberized fabric, the adjacent edges 1 of which are parallel, but with a space between substantially equal to the diameter of the reduced part 5 of the valve stem 6 adjacent the head 7 thereof, as shown in Fig. 4.

1n constructing these patches 2 and 3 they may be cut to proper form and size by an oval die which will cut the pair of patches, or an oval of proper size may be marked on a fabric, the major axis of the oval being bias or diagonal to the weft and warp threads, and then an oval blank is severed from its web and the blank be then severed on its major axis or longitudinal center, and the two patches 2 and 3 of fabric laid upon a sheet or blank l of unvulcanized rubber with the severed edges i parallel and spaced apart a distance substantially equal to the diameter of the reduced part 5 of the valve stem 6 adjacent the head 7.

The patches 8 and 9 are formed from the same fabric, the longer axis of the oval being, in this case, parallel with one set of threads and at right angles to the other set, and these patches are severed laterally on the minor axis of the oval and the parts laid on that side of the rubber blank l opposite the patches 2 and 3 with their parallel edges spaced apart, as in Fig. 8.` The positions of the two pairs of patches with relation to each other, and the pad with relationto the tube, are well illustrated in Fi .2.

'zlglhe spaces between the parallel edges of the patches 2 and 3 and 8 and 9 will be filled with strips 10 of unvulcanized rubber of a thickness equal to that of the fabric in order to form a continuous surface for contact with the usual washer 11 defining the limit of the valve stem and the opposing surface 12 of the head or button 7 of the valve stem.

A strip 10 of unvulcanized rubber is placed between the edges of the two patches 2 3 and 8 and 9 of fabric of each layer and the strips of .each of the two layers are at a right angle to the strip of the other layer. rlhe fabric of the layer of patches 8 and 9 which has its intervening strip at right angles or transverse tothe direction of the travel of the tire is cut straight, while that of the layers 2 and 3 having the intervening strip in the direction of the travel of the tire is cut bias or diagonal.

This is of importance as not only rendering a close Contact adjacent the reduced portion or base of the valve stem, but in con- Leeaee nection with the intervening strips of unvul- W canized rubber will prevent air holes of the pad while being rolled in embodying or con; necting it with the tube or blistering in vulcanization.

The pad or stem base so far described is designed for employment with inner tubes of tires of the smaller diameters used on wheels for the lighter types of motor cars and the like. For heavier tires 1 increase the thickness of the pad, as in Figs. 5, G and 7, by the addition of one or more pairs of patches constructed in all respects like those heretofore described except for the addition of other thicknesses; as, for instance, as shown in the longitudinal section, Fig. 7, the uppermost patches may be of fabric with the threads arranged straight with relation to the circumference of the tire; that is to say, one series of threads will be parallel with the major axis of the oval and the other series parallel with the minor axis thereof so that there can be no stretch of the fabric either longitudinally or transversely, though the filling strips 10 and interposed rubber sheet 1, which are integral after vulcanization, will permit limited stretch of the pad, as a whole, longitudinally. The next lower thickness will be of unvulcanized rubber, and the next below will be of fabric` the weft and warp threads of which will be .diagonal to the parallel edges 4.

As the opposing edges of the patches 2 and 3 and the patches 8 and 9 will fit snugly against the reduced part 5 of the valve stem, and the filler strips l() will maintain the continuity of surface of a given layer or thickness of the pad, it is apparent that there will be no tendency of leak at this junction of the valve stem and the valve-stem aperture of the tube; and, moreover, the opposing surfaces of the valve stem head and the washer will have an even surface to clamp between them.

I claim:

l. A base or pad for the valve stem of pneumatic tires and the like,` consisting of superposed pairs of spaced apart fabric patches with interposed rubber, the weft and woof threads of one pair of patches being arranged diagonally with relation to another pair of patches, and the spaces between the parallel edges of the respective pairs of patches crossing at right angles.

2. rl`he combination with the air tube of a pneumatic tire or the like, of an embedded pad consisting of superposed pairs of spaced apart fabric patches with interposed rubber having the threads of one pair arranged diagonally with relation to another pair, and the rubber filled spaces between the respective pairs crossing at right angles.

3. An air tube for pneumatic tires provided with an integral valve-stem pad comprising pairs of fabric patches spaced apart,

1 ,ac3 ,ese

the threads of said patches being diagonal to the circumferential line of the tube, and

pairs of spaced apart fabric patches, the threads of which are parallel and transverse to the circumferential line of the tube, and unvulcanized rubber interposed between said pairs of patches.

4. An inflatable tube or the like provided with a valve pad consisting of a plurality of superposed layers of fabric with an intervening layer of rubber, each of said fabric layers being formed of two separated fabric patches with an intervening rubber strip extending along the entire Separated lengths of said patches, and the patches of one of said fabric layers being cut bias or diagonal, while that of the other is cut straight, substantially as described.

5. An inflatable tire tube or the like provided witli a valve pad consisting of a plurality of superposed layers of fabric with an intervening layer of rubber, each of said fabric layers being formed of a pair of patches separated along their entire lengths and provided with an intervening strip of rubber, substantially as described.

6. A tube for a tire carrying a plurality of fabric layers with an intervening layer of rubber, said fabric layers being each formed of a pair of separated patches of fabric with an intervening strip vof rubber, the rubber strip of one fabric being at right angles to that of the other fabric layer and the fabric of the layer having its strip transverse to the travel of the tire being cut straight, while that of another layer is cut.

diagonal or bias, substantially as described.

7. A tube for a tire having embedded therein a pad consisting of a plurality of layers of fabric with an intervening layer of rubber, each of said layers of fabric being formed of a pair of separated patches, the material of one of which is cut bias and the material of the other cut straight and said patches havin between them a strip of rubber, 'substantial y as described.

8. A tube for a tire carrying a pad consisting of a plurality of layers of fabric with an intervening layer of rubber, each of said layers of fabric being formed of 'patches separated along their entire lengths by intervening strips of rubber, substantially as described.

9. A tube for a tire carrying a pad consisting of a plurality of layers of fabric and an intervening layer of rubber, the fabric layers each being formed of. a pair of separated fabric patches with an intervening strip of rubber and the rubber strip of one of said fabric layers being at a right angle to the strip of another fabric layer, substantially as described.

10. A tube for pneumatic tires havinga reinforced pad embedded therein, said pad consisting of a plurality of layers of material, each layer being formed of two pieces of non-elastic fabric separated from each other along their entire lengths and having a filling piece in the intervening space; the filling vpieces of the said layers being of rubber` and arranged at right angles to each other, the fabric of one of the layers, that having its filling piece which extends in the direction of the travel of the tube, cut bias,v

while the fabric of the other layer is cut straight, substantially as described.

` 11. A tube for pneumatic tires carrying a valve-stem pad vcomprising patches of fabric separated from each other along their entire len hs with filling strips of rubber, substantia ly as described.

12. A tube for pneumatic tires, having an I opening therethrough, land a plurality of superposed staggered strips vulcanized in the body thereof, the Ainner edges of said 'strips being adjacent to the opening, whereby when the head of a valve stem is inserted through the opening the rubber will expand and permit the strips of material to move relatively to one another.

In testimony whereof I affix m signature.

WILLIAM F. ISHOP. 

